Multi-scale performance evaluation of ejector refrigeration systems

Despite the many advantages, ejector refrigeration systems have not been able to penetrate the market because of two prevailing reasons: low coefficient of performance and relevant influence of ejector operation on the performance of the whole system. Indeed, the performance of ejector refrigeration systems depends on the local flow phenomena occurring within the ejector. Thus, improving the performance of ejector refrigeration systems relies on the understanding of the fluid dynamic phenomena at the "component-scale"and on integrating such information at the "system-scale". This paper contributes to the present discussion regarding the multi-scale modeling of ejector-based systems by proposing an integrated Computational Fluid Dynamic (CFD) - Lumped Parameter Model (LPM) ejector refrigeration system. In particular, ejector performances have been obtained by a validated CFD approach, whereas a LPM approach has modeled the refrigeration cycle. The refrigeration system's performances, for different boundary conditions, have been evaluated, and the effects of the "local-scale"on the "system-scale"have been commented.